An adaptive active balanced charge and discharge switching circuit

Abstract

The utility model discloses an adaptive active balanced charge and discharge switching circuit, comprising: a transformer, a control module, a first switch module and a second switch module; the control end of the first switch module is electrically connected to the first signal output end of the control module; one end of the primary winding of the transformer is electrically connected to the power supply end; the other end of the primary winding of the transformer is grounded after passing through the controlled end of the first switch module; the control end of the second switch module is electrically connected to the second signal output end of the control module; one end of the secondary winding of the transformer is electrically connected to the positive pole of the battery; the other end of the secondary winding of the transformer is electrically connected to the negative pole of the battery after passing through the controlled end of the second switch module. The utility model utilizes PWM complementation to realize bidirectional synchronous rectification, thereby improving work efficiency, and the current does not need to be rectified through a diode, so current loss will not be caused, and abnormal temperature increase of the device will not be caused, so the device temperature can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage equipment, and in particular to an adaptive active balanced charging and discharging switching circuit. Background Art

[0002] In existing active balancing circuits, bidirectional DCDC is often used as an energy converter. When the battery needs to be charged, the DCDC current is transmitted in the forward direction, and when the battery needs to be discharged, the DCDC current is transmitted in the reverse direction, realizing the transfer of battery power to achieve the purpose of balancing.

[0003] like Figure 1 As shown, the existing bidirectional DCDC converter is equivalent to using two independent flyback switching power supplies. During the charging process, the control chip U3 controls the MOS tube Q7 to turn on; the control chip U4 controls the MOS tube Q8 to be in the off state; the output current is rectified by the diode D4 to charge the battery, R14 is the current detection resistor, when the current reaches the set value, U6 is turned on, and the current state is fed back to U3 through the FB1 pin of U6, realizing the current closed-loop control. During the discharging process, the control chip U3 controls the MOS tube Q7 to turn off; the control chip U4 controls the MOS tube Q8 to turn on; the output current is rectified by D3 to make the output end charge the power supply in reverse, R14 is the sampling resistor, the current at both ends of R14 flows from left to right, when the set value is reached, U5 is turned on, and the current state is fed back to U4 through the FB2 of U5, realizing the current open-loop control.

[0004] However, in this charging and discharging method, because the current must be rectified by diode D3 or D4, the voltage drop of the rectifier tube is large, the current loss is high, and the device temperature is high. In addition, this topology generally sets a fixed current value, and the current cannot be edited, so it is not suitable for use in precision calculation application scenarios. Utility Model Content

[0005] The utility model aims to disclose an adaptive active balanced charge and discharge switching circuit, which solves the defects of the existing charge and discharge circuit that the current cannot be accurately edited and the use of diode rectification leads to large voltage drop and large power loss.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] An adaptive active balanced charge and discharge switching circuit comprises: a transformer for connecting to a battery to adjust the charging voltage or discharging voltage of the battery; a control module for outputting a first conduction signal or a second conduction signal; a first switch module for responding to the first conduction signal generated by the control module to control the conduction of the primary winding of the transformer; a second switch module for responding to the second conduction signal generated by the control module to control the conduction of the secondary winding of the transformer; a control end of the first switch module is electrically connected to a first signal output end of the control module; one end of the primary winding of the transformer is electrically connected to a power supply end; the other end of the primary winding of the transformer is grounded after passing through a controlled end of the first switch module; the control end of the second switch module is electrically connected to a second signal output end of the control module; one end of the secondary winding of the transformer is electrically connected to a positive electrode of the battery; the other end of the secondary winding of the transformer is electrically connected to a negative electrode of the battery after passing through a controlled end of the second switch module.

[0008] Optionally, the control module includes: a single-chip microcomputer for generating complementary first PWM signals and second PWM signals, and a signal conversion unit for outputting a first conduction signal or a second conduction signal according to the duty cycle of the first PWM signal and the duty cycle of the second PWM signal; a first output end of the single-chip microcomputer is electrically connected to a first input end of the signal conversion unit; a second output end of the single-chip microcomputer is electrically connected to a second input end of the signal conversion unit; a first signal output end of the signal conversion unit is electrically connected to a control end of the first switch module; and a second signal output end of the signal conversion unit is electrically connected to a control end of the second switch module.

[0009] Optionally, the first switch module includes: a first MOS tube and an eighth resistor; the gate of the first MOS tube is electrically connected to the first signal output end of the signal conversion unit after passing through the eighth resistor; the source of the first MOS tube is grounded; and the drain of the first MOS tube is electrically connected to the other end of the primary winding of the transformer.

[0010] Optionally, the second switch module includes: an optical isolator, a ninth resistor, a tenth resistor, and a second MOS tube; the first pin of the optical isolator is electrically connected to the second signal output end of the signal conversion unit; the third pin of the optical isolator is grounded after passing through the tenth resistor; the fourth pin of the optical isolator is grounded; the fifth pin of the optical isolator is electrically connected to the gate of the second MOS tube after passing through the ninth resistor; the sixth pin of the optical isolator is electrically connected to the power supply end; the source of the second MOS tube is grounded; the source of the second MOS tube is also electrically connected to the negative electrode of the battery; the drain of the second MOS tube is electrically connected to the other end of the secondary winding of the transformer.

[0011] Optionally, it also includes: a sampling resistor for detecting the current between the transformer and the battery, and a sampling chip for generating a feedback signal according to the current in the sampling resistor; one end of the sampling resistor is electrically connected to the source of the second MOS tube; the other end of the sampling resistor is electrically connected to the negative electrode of the battery; the first input end and the second input end of the sampling chip are electrically connected to the two ends of the sampling resistor respectively; the output end of the sampling chip is electrically connected to the control module.

[0012] Optionally, it also includes: a first filter capacitor; the positive electrode of the first filter capacitor is electrically connected to the positive electrode of the battery, and the negative electrode of the first filter capacitor is electrically connected to the negative electrode of the battery after passing through a sampling resistor.

[0013] Optionally, it also includes: a second filter capacitor; the positive electrode of the second filter capacitor is electrically connected to one end of the primary winding of the transformer; and the negative electrode of the second filter capacitor is grounded.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model provides an adaptive active balanced charge and discharge switching circuit. The application utilizes a single chip microcomputer to output two complementary PWMs to realize the control of a DCDC converter. This control method is more convenient to control, and can utilize PWM complementarity to realize bidirectional synchronous rectification, thereby improving working efficiency. Moreover, the current does not need to be rectified through a diode, and will not cause current loss or abnormal increase in device temperature, thereby effectively reducing the device temperature. Moreover, the circuit of the application can automatically identify the PWM widths of PWM1 and PWM2, distinguish the working states of the two, respectively output control signals to control corresponding rectifier devices, and can identify whether the DCDC converter is working in a charging or discharging state. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a schematic diagram of a charge and discharge switching circuit in the prior art;

[0018] Figure 2 This is a circuit schematic diagram of an adaptive active balanced charge and discharge switching circuit of the utility model;

[0019] Figure 3 4 is a circuit diagram of the signal conversion unit of Example 2. DETAILED DESCRIPTION

[0020] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0021] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical", "horizontal", "left", "right", "above", "below" and similar expressions are for illustrative purposes only, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] Embodiment 1

[0024] like Figure 2An adaptive active balanced charge and discharge switching circuit shown includes: a transformer T1 for connecting to a battery to adjust the charging voltage or discharging voltage of the battery; a control module for outputting a first conduction signal or a second conduction signal; a first switch module 2 for responding to the first conduction signal generated by the control module to control the conduction of the primary winding of the transformer; a second switch module 3 for responding to the second conduction signal generated by the control module to control the conduction of the secondary winding of the transformer; the control end of the first switch module is electrically connected to the first signal output end of the control module; one end of the primary winding of the transformer is electrically connected to the power supply end; the other end of the primary winding of the transformer is grounded after passing through the controlled end of the first switch module; the control end of the second switch module is electrically connected to the second signal output end of the control module; one end of the secondary winding of the transformer is electrically connected to the positive electrode of the battery; the other end of the secondary winding of the transformer is electrically connected to the negative electrode of the battery after passing through the controlled end of the second switch module.

[0025] In summary, the present application utilizes the control module to output a conduction signal corresponding to the control of the MOS tube to realize the control of the DCDC converter. This control method is more convenient to control. Specifically, in the control module, a single-chip microcomputer is used to output two PWM complementary signals to realize bidirectional synchronous rectification, and a signal conversion unit 1 is used to convert the two complementary PWM signals into corresponding conduction signals, which are applied to the battery charge and discharge switching module. The work efficiency can be improved, and the current does not need to be rectified through a diode, which will not cause current loss or abnormal increase in the temperature of the equipment, and can effectively reduce the temperature of the equipment. The active balanced charge and discharge circuit of the present application can automatically identify the PWM width of PWM1 and PWM2, distinguish the working states of the two, output control signals to control the corresponding rectifier devices respectively, and can identify whether the DCDC converter is working in the charging or discharging state, which can effectively meet the bidirectional startup control of the DCDC flyback converter.

[0026] Complementary PWM signals mean that when PWM1 is high, PWM2 is low, and vice versa, when PWM1 is low, PWM2 is high. Therefore, when the signal starts to be output, the duty cycle of PWM1 is 1% and the duty cycle of PWM2 is 99%. Under the output control of the microcontroller, the duty cycle of PWM1 gradually increases, and correspondingly, the duty cycle of PWM2 gradually decreases. At the initial operation, PWM1 is less than the on time of PWM2. At this time, VB+ will flow to the secondary of the transformer due to the on-state of the second MOS tube Q4, causing discharge. It will not turn to charging until PWM1 is greater than PWM2. When charging, it will discharge first, and when discharging, it will charge first, which will cause energy waste. In order to solve the problem of reverse charging during charging and discharging, it is necessary to drive the first MOS tube Q3 to turn on when the duty cycle of PWM1 is very small at the beginning of charging, and prohibit PWM2 from turning on Q4 to prevent the positive electrode VB+ current of the battery from reverse charging. At this time, the secondary current will be rectified through the internal parasitic diode of the second MOS tube Q4. As the duty cycle of PWM1 increases, the secondary output voltage also increases. When the voltage rises to higher than VB+, charging begins. At this time, PWM2 turns on the second MOS tube Q4 for synchronous rectification, and the entire soft start charging process ends. The principle of discharging is the same. At the beginning of discharging, when the duty cycle of PWM2 is very small, the second MOS tube Q4 is driven to turn on, and PWM1 is prohibited from turning on the first MOS tube Q3. At this time, the secondary current will be rectified through the internal parasitic diode of the first MOS tube Q3. As the duty cycle of PWM2 increases, the output voltage of the primary coil also increases. When the voltage rises to higher than VDD, charging begins. At this time, PWM1 turns on the first MOS tube Q3 for synchronous rectification, and the entire soft start charging process ends.

[0027] The control module includes: a single-chip microcomputer (not shown in the figure) for generating complementary first PWM signals and second PWM signals, and a signal conversion unit 1 for outputting a first conduction signal or a second conduction signal according to the duty cycle of the first PWM signal and the duty cycle of the second PWM signal; a first output end of the single-chip microcomputer is electrically connected to a first input end of the signal conversion unit 1; a second output end of the single-chip microcomputer is electrically connected to a second input end of the signal conversion unit 1; a first signal output end of the signal conversion unit 1 is electrically connected to a control end of a first switch module; and a second signal output end of the signal conversion unit 1 is electrically connected to a control end of a second switch module.

[0028] Specifically, in the present application, the drive control signal output by the single-chip microcomputer is two mutually complementary PWM signals, and the signal conversion unit is used to output a corresponding conduction signal according to the duty cycle of the PWM signal. Specifically, when the duty cycle of the first PWM signal is smaller than that of the second PWM signal, the first signal output end of the signal conversion unit (that is, the 5th pin of the signal conversion unit) outputs the conduction signal; when the duty cycle of the first PWM signal is greater than that of the second PWM signal, the first signal output end of the signal conversion unit (that is, the 7th pin of the signal conversion unit) outputs the conduction signal.

[0029] During the charging process, the first PWM signal starts with a duty cycle of 1%, and the second PWM signal starts with a duty cycle of 99%. At this time, the OUTB channel of the signal conversion unit 1 is opened, the second PWM signal drives the second MOS tube Q4 to turn on, and the OUTA channel of the signal conversion unit 1 is closed, so that the second MOS tube Q4 is cut off to prevent the secondary current from being reversely charged. As the duty cycle of PWM1 increases, the duty cycle of PWM2 decreases, the OUTA channel of the signal conversion unit 1 is opened, and the first PWM signal drives the first MOS tube Q3 to work, thereby realizing the charging switching process.

[0030] During the discharge process, the starting duty cycle of the second PWM signal is 1%, and the starting duty cycle of the first PWM signal is 99%; the OUTA channel of the signal conversion unit 1 is opened, and the second PWM signal drives the second MOS tube Q4 to start working. At this time, the second capacitor C4 is charged lower than the first capacitor C3, so the fourth transistor Q5 is turned off, and the second transistor Q2 is also turned off. The point B corresponding to the collector of the second transistor is a low level, and the enable B channel of the signal conversion unit 1 is closed, so that the first MOS tube Q3 is turned off to prevent the primary current from being reversely charged. As the duty cycle of the second PWM signal increases, the voltage of the second capacitor C4 also rises. When the voltage of the second capacitor C4 rises to the same level as the voltage of the first capacitor C3, the fourth transistor Q5 is turned on, and the point B corresponding to the collector of the second transistor Q2 outputs a high level. The enable B channel of the signal conversion unit 1 is opened, and the second PWM signal drives the second MOS tube Q4 to work, realizing the discharge switching process.

[0031] Furthermore, the first switch module includes: a first MOS tube Q3 and an eighth resistor R8; the gate of the first MOS tube Q3 is electrically connected to the first output end (that is, the enable A output end) of the signal conversion unit 1 after passing through the eighth resistor R8; the source of the first MOS tube Q3 is grounded; and the drain of the first MOS tube Q3 is electrically connected to the other end of the primary winding of the transformer T1.

[0032] Furthermore, the second switch module includes: an optical isolator U1, a ninth resistor R9, a tenth resistor R10, and a second MOS tube Q4; the first pin of the optical isolator U1 is electrically connected to the second output end (that is, the enable B output end) of the signal conversion unit 1; the third pin of the optical isolator U1 is grounded after passing through the tenth resistor R10; the fourth pin of the optical isolator U1 is grounded; the fifth pin of the optical isolator U1 is electrically connected to the gate of the second MOS tube Q4 after passing through the ninth resistor R9; the sixth pin of the optical isolator U1 is electrically connected to the power supply end; the source of the second MOS tube Q4 is grounded; the source of the second MOS tube Q4 is also electrically connected to the negative electrode VB- of the battery; the drain of the second MOS tube Q4 is electrically connected to the other end of the secondary winding of the transformer T1.

[0033] Specifically, in this application, in order to reduce the impact of the charging and discharging process on the MOS tube, this application sets an optical isolator in the second switch module, which can effectively isolate the input ground VDD from the voltage between the battery. The ninth resistor provides a current limiting function to prevent excessive input current from affecting the normal operation of the MOS tube.

[0034] Furthermore, it also includes: a sampling resistor R11 and a sampling chip U2; one end of the sampling resistor R11 is electrically connected to the source of the second MOS tube Q4; the other end of the sampling resistor R11 is electrically connected to the negative electrode VB- of the battery; the first input end and the second input end of the sampling chip U2 are electrically connected to the two ends of the sampling resistor R11 respectively; the output end ADC of the sampling chip is electrically connected to the single chip computer for outputting the PWM signal.

[0035] Specifically, the sampling resistor is set between the negative pole of the battery and the secondary winding of the transformer. The sampling resistor is detected by the sampling chip, and the current in the sampling resistor is fed back to the single-chip microcomputer that outputs the PWM signal to realize feedback control. During the charging process, the single-chip microcomputer MCU outputs PWM1 and PWM2 to drive the first MOS tube Q3 and the second MOS tube Q4 through the current amplification of the signal conversion unit 1 respectively. When the PWM1 high level drives the first MOS tube Q3 to turn on, the VDD current flows to the primary winding of the transformer to store energy. Then PWM1 turns to a low level to turn off the first MOS tube Q3, and PWM2 outputs a high level to drive the second MOS tube Q4 to turn on. At this time, the transformer reverses the secondary to release energy, and the current flows through the VB+ to the positive pole of the battery through the negative pole of the battery, and flows back to the secondary winding of the transformer through the second MOS tube Q4, completing a working cycle. R11 is a current sampling resistor, and the sampling chip feeds back the current state to the MCU through the ADC to realize current closed-loop control.

[0036] During the discharge process, the single-chip microcomputer MCU outputs PWM1 and PWM2 respectively drive the first MOS tube Q3 and the second MOS tube Q4 through the current amplification of the signal conversion unit 1. When PWM2 is high and drives Q4 to turn on, the VB+ current flows to the secondary winding of the transformer to store energy. Then PWM2 turns to a low level to turn off Q4. At the same time, PWM1 outputs a high level to drive the first MOS tube Q3 to turn on. At this time, the transformer reverses the primary to release energy. The current output from the transformer pin 1 flows through VDD and the positive electrode of the power supply through the negative electrode of the power supply (GNG) in turn, and then flows back to the primary winding of the transformer pin 2 through the source of the first MOS tube Q3 and the drain of the first MOS tube Q3, completing a working cycle. At this time, R11 is a current sampling resistor, and the sampling chip feeds back the current state to the MCU through the ADC to realize current open-loop control.

[0037] Furthermore, it also includes: a first filter capacitor C1; the positive electrode of the first filter capacitor C1 is electrically connected to the positive electrode of the battery, and the negative electrode of the first filter capacitor C1 is electrically connected to the negative electrode of the battery after passing through a sampling resistor.

[0038] Furthermore, it also includes: a second filter capacitor C2; the positive electrode of the second filter capacitor C2 is electrically connected to one end of the primary winding of the transformer T1; and the negative electrode of the second filter capacitor C2 is grounded.

[0039] Example 2

[0040] Furthermore, the present application provides a signal conversion unit that can convert two complementary PWM signals output by the single-chip microcomputer into level signals, thereby controlling the conduction of the first MOS tube or the second MOS tube. Specifically, the signal conversion unit includes: a first transistor Q1, a second transistor Q2, a third transistor Q6, a fourth transistor Q5, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first capacitor C3, a second capacitor C4, a first voltage zener diode D1, and a second voltage zener diode D2; an anode of the first voltage zener diode D1 is electrically connected to a first PWM signal input terminal; a cathode of the first voltage zener diode D1 is electrically connected to a base of the third transistor Q6 after passing through a fifth resistor R5; a base of the third transistor Q6 is grounded after passing through a first capacitor C3; an anode of the second voltage zener diode D2 is electrically connected to a second PWM signal output terminal; a cathode of the second voltage zener diode D2 is electrically connected to a base of the fourth transistor Q5 after passing through a sixth resistor R6; a base of the fourth transistor Q5 is grounded after passing through a second capacitor C4; The emitter of the third transistor Q6 is electrically connected to the emitter of the fourth transistor Q5; the emitter of the third transistor Q6 is also grounded after passing through the seventh resistor R7; the collector of the third transistor Q6 is electrically connected to the base of the first transistor Q1; the collector of the third transistor Q6 is also electrically connected to the collector of the first transistor Q1 after passing through the first resistor R1; the collector of the first transistor Q1 is electrically connected to the power supply terminal VCC; the emitter of the first transistor Q1 is grounded after passing through the third resistor R3; the emitter of the first transistor Q1 is also electrically connected to the control end of the first switch module; the collector of the fourth transistor Q5 is electrically connected to the base of the second transistor Q2; the collector of the fourth transistor Q5 is also electrically connected to the emitter of the second transistor Q2 after passing through the second resistor R2; the emitter of the second transistor Q2 is electrically connected to the power supply terminal VCC; the collector of the second transistor Q2 is grounded after passing through the fourth resistor R4; the collector of the second transistor Q2 is also electrically connected to the control end of the second switch module.

[0041] In the charging process, the first PWM signal starts with a duty cycle of 1%, and the second PWM signal starts with a duty cycle of 99%. At this time, the first capacitor C3 charges slowly, and the second capacitor C4 charges quickly. The fourth transistor Q5 is turned on first to bias the second transistor Q2, and the second transistor Q2 is turned on. The output terminal B outputs a high level, the OUTB channel of the soft start module 1 is turned on, and the second PWM signal drives the second MOS tube Q4 to turn on. At this time, the first capacitor C3 is charged lower than the second capacitor C4, so the third transistor Q6 is turned off, the first transistor Q1 is also turned off, and the emitter point A of the first transistor is low level. The OUTA channel of the soft start module 1 is closed, so that the second MOS tube Q4 is turned off to prevent the secondary current from being reversely charged. As the duty cycle of PWM1 increases, the duty cycle of PWM2 decreases, and the voltage of C3 also rises accordingly. When the voltage of C3 rises to the same level as the voltage of C4, the third transistor Q6 is turned on, point A turns to a high level, the OUTA channel of the soft start module 1 is turned on, and the first PWM signal drives the first MOS tube Q3 to work, thereby realizing the charging switching process.

[0042] During the discharge process, the starting duty cycle of the second PWM signal is 1%, and the starting duty cycle of the first PWM signal is 99%; at this time, the second capacitor C4 charges slowly, and the first capacitor C3 charges quickly. The third transistor Q6 is turned on first to bias the first transistor Q1, and the first transistor Q1 is turned on. Point A of the emitter of the first transistor Q1 is at a high level, and the enable channel A of the soft start module 1 is turned on. The second PWM signal drives the second MOS tube Q4 to start working. At this time, the second capacitor C4 is charged lower than the first capacitor C3, so the fourth transistor Q5 is turned off, and the second transistor Q2 is also turned on. The first MOS tube Q3 is cut off, the point B corresponding to the collector of the second transistor is at a low level, the enable B channel of the soft start module 1 is closed, and the first MOS tube Q3 is cut off to prevent the primary current from being reversely charged. As the duty cycle of the second PWM signal increases, the voltage of the second capacitor C4 also rises accordingly. When the voltage of the second capacitor C4 rises to be consistent with the voltage of the first capacitor C3, the fourth transistor Q5 is turned on, and the point B corresponding to the collector of the second transistor Q2 outputs a high level. The enable B channel of the soft start module 1 is opened, and the second PWM signal drives the second MOS tube Q4 to work, thereby realizing the discharge switching process.

[0043] In summary, the present application utilizes the control module to output a conduction signal corresponding to the control of the MOS tube to realize the control of the DCDC converter. This control method is more convenient to control. Specifically, in the control module, a single-chip microcomputer is used to output two PWM complementary signals to realize bidirectional synchronous rectification, and a signal conversion unit 1 is used to convert the two complementary PWM signals into corresponding conduction signals, which are applied to the battery charge and discharge switching module. The work efficiency can be improved, and the current does not need to be rectified through a diode, which will not cause current loss or abnormal increase in the temperature of the equipment, and can effectively reduce the temperature of the equipment. The active balanced charge and discharge circuit of the present application can automatically identify the PWM width of PWM1 and PWM2, distinguish the working states of the two, output control signals to control the corresponding rectifier devices respectively, and can identify whether the DCDC converter is working in the charging or discharging state, which can effectively meet the bidirectional startup control of the DCDC flyback converter.

[0044] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the claims of the present invention and the scope of equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. An adaptive active balanced charge and discharge switching circuit, characterized in that: include: A transformer for connecting to a battery to adjust the charging voltage or discharging voltage of the battery; A control module for outputting a first conduction signal or a second conduction signal; A first switch module for controlling the conduction of the primary winding of the transformer in response to a first conduction signal generated by the control module; A second switch module for controlling the conduction of the secondary winding of the transformer in response to a second conduction signal generated by the control module; The control end of the first switch module is electrically connected to the first signal output end of the control module; one end of the primary winding of the transformer is electrically connected to the power supply end; the other end of the primary winding of the transformer is grounded after passing through the controlled end of the first switch module; The control end of the second switch module is electrically connected to the second signal output end of the control module; one end of the secondary winding of the transformer is electrically connected to the positive pole of the battery; the other end of the secondary winding of the transformer is electrically connected to the negative pole of the battery after passing through the controlled end of the second switch module.

2. The adaptive active balanced charge-discharge switching circuit according to claim 1, characterized in that: The control module includes: a single chip computer for generating a complementary first PWM signal and a second PWM signal, and a signal conversion unit for correspondingly outputting a first conduction signal or a second conduction signal according to the duty cycle of the first PWM signal and the duty cycle of the second PWM signal; The first output terminal of the single chip microcomputer is electrically connected to the first input terminal of the signal conversion unit; The second output terminal of the single chip microcomputer is electrically connected to the second input terminal of the signal conversion unit; The first signal output terminal of the signal conversion unit is electrically connected to the control terminal of the first switch module; The second signal output terminal of the signal conversion unit is electrically connected to the control terminal of the second switch module.

3. The adaptive active balanced charge-discharge switching circuit according to claim 2, characterized in that: The first switch module includes: a first MOS tube and an eighth resistor; The gate of the first MOS tube is electrically connected to the first signal output end of the signal conversion unit after passing through the eighth resistor; the source of the first MOS tube is grounded; and the drain of the first MOS tube is electrically connected to the other end of the primary winding of the transformer.

4. The adaptive active balanced charge-discharge switching circuit according to claim 2, characterized in that: The second switch module includes: an optical isolator, a ninth resistor, a tenth resistor, and a second MOS tube; The first pin of the optical isolator is electrically connected to the second signal output terminal of the signal conversion unit; the third pin of the optical isolator is grounded after passing through the tenth resistor; the fourth pin of the optical isolator is grounded; the fifth pin of the optical isolator is electrically connected to the gate of the second MOS tube after passing through the ninth resistor; the sixth pin of the optical isolator is electrically connected to the power supply terminal; The source of the second MOS tube is grounded; the source of the second MOS tube is also electrically connected to the negative electrode of the battery; the drain of the second MOS tube is electrically connected to the other end of the secondary winding of the transformer.

5. An adaptive active balanced charge-discharge switching circuit according to any one of claims 1 to 4, characterized in that: Also includes: A sampling resistor for detecting the current between the transformer and the battery and a sampling chip for generating a feedback signal according to the current in the sampling resistor; One end of the sampling resistor is electrically connected to the source of the second MOS tube; the other end of the sampling resistor is electrically connected to the negative electrode of the battery; The first input terminal and the second input terminal of the sampling chip are electrically connected to the two ends of the sampling resistor respectively; and the output terminal of the sampling chip is electrically connected to the control module.

6. The adaptive active balanced charge-discharge switching circuit according to claim 1, characterized in that: Also includes: A first filter capacitor; a positive electrode of the first filter capacitor is electrically connected to the positive electrode of the battery, and a negative electrode of the first filter capacitor is electrically connected to the negative electrode of the battery after passing through a sampling resistor.

7. The adaptive active balanced charge-discharge switching circuit according to claim 1, characterized in that: Also includes: The second filter capacitor; The positive electrode of the second filter capacitor is electrically connected to one end of the primary winding of the transformer; The negative electrode of the second filtering capacitor is grounded.

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